BCer Monkeyboy is not so easily distracted by shiny brown baubles and has been doing a bit of digging about what an "interchange hub" could actually be. He's elicited this snippet from TfL, who have confirmed that while the plans are in their infancy, it would be implemented independently of the Bakerloo project. They say:The potential interchange at Brockley is currently an unfunded and uncommitted scheme and no detailed plans exist at present. However, we have identified the potential new interchange hub as an option for improving rail connectivity in south east London and as a complimentary scheme to a potential Bakerloo line extension to Lewisham. We do not consider the option to be dependent on the proposed Bakerloo line extension so yes it is possible that the hub could be implemented independently.Along with the other potential long term wider region rail improvements included in the Summary Report, we are working with stakeholders and partners, including Network Rail, to undertake further assessment of their benefits and feasibility.
Given that Brockley's links to London Bridge and on the East London Line will reach their current limits when a couple more ELL trains are squeezed on to our line in 2018, it's likely that TfL's ideas relate to the reopening of the upper line platform as part of a new orbital link, connecting Brockley with Lewisham and Peckham and beyond.